#113 Broken pipe (mixer) upon start

[Moonbase]

I’m trying to run IDJC on EndeavourOS (Arch-based), using the AUR version 0.9.9-1. This works fine on my Toshiba Satellite L70-B, but not on my Thinkpad T14 Gen 1. Since both installations are almost perfectly identical, I somehow suspect the interaction between IDJC and the Thinkpad soundcard, because it has a crazy number of mixer controls.

My error message when starting IDJC:

$ idjc
jack client ID: idjc_t14
idjc 0.9.9
cpython 3.13.7 (main, Aug 15 2025, 12:34:02) [GCC 15.2.1 20250813]
IRC support requires python-irc: not installed
launching backend
backend launch attempt 1
libshout-idjc version 2.4.6
started 6 encoders, 6 streamers, 2 recorders
player read buffer allocated for 1024 frames
player read buffer allocated for 256 frames
player read buffer allocated for 1024 frames
player read buffer allocated for 256 frames
awaiting status message from back-end
reply='idjc backend ready\n'
[Errno 32] Datenübergabe unterbrochen (broken pipe)
backend launch attempt 1
libshout-idjc version 2.4.6
started 6 encoders, 6 streamers, 2 recorders
player read buffer allocated for 1024 frames
player read buffer allocated for 256 frames
player read buffer allocated for 1024 frames
player read buffer allocated for 256 frames
Exception ignored in: <_io.TextIOWrapper name=16 mode='w' encoding='UTF-8'>
Traceback (most recent call last):
  File "/usr/lib/idjc/site-packages/idjc/maingui.py", line 2680, in mixer_write
    self._mixer_ctrl = os.fdopen(write.value, "w")
BrokenPipeError: [Errno 32] Datenübergabe unterbrochen (broken pipe)
awaiting status message from back-end
reply='idjc backend ready\n'
Traceback (most recent call last):
  File "/usr/lib/idjc/site-packages/idjc/maingui.py", line 2664, in mixer_write
    self._mixer_ctrl.flush()
    ~~~~~~~~~~~~~~~~~~~~~~^^
BrokenPipeError: [Errno 32] Datenübergabe unterbrochen (broken pipe)

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/bin/idjc", line 38, in <module>
    exit(idjc.main())
         ~~~~~~~~~^^
  File "/usr/lib/idjc/site-packages/idjc/__init__.py", line 134, in main
    return main()
  File "/usr/lib/idjc/site-packages/idjc/maingui.py", line 4033, in main
    run_instance = MainWindow()
  File "/usr/lib/idjc/site-packages/idjc/maingui.py", line 3928, in __init__
    self.jack = JackMenu(self.menu, lambda s, r: self.mixer_write(
                ~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
                "ACTN=jack%s\n%s" % (s, r)), lambda: self.mixer_read())
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/idjc/site-packages/idjc/maingui.py", line 239, in __init__
    if self.list_ports("hwoutputs")[0].startswith("system:"):
       ~~~~~~~~~~~~~~~^^^^^^^^^^^^^
  File "/usr/lib/idjc/site-packages/idjc/maingui.py", line 414, in list_ports
    self.write("portread", f"JFIL={filter_}\nJPRT=\nend\n")
    ~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/idjc/site-packages/idjc/maingui.py", line 3928, in <lambda>
    self.jack = JackMenu(self.menu, lambda s, r: self.mixer_write(
                                                 ~~~~~~~~~~~~~~~~^
                "ACTN=jack%s\n%s" % (s, r)), lambda: self.mixer_read())
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/idjc/site-packages/idjc/maingui.py", line 2703, in mixer_write
    self.send_new_mixer_stats()
    ~~~~~~~~~~~~~~~~~~~~~~~~~^^
  File "/usr/lib/idjc/site-packages/idjc/maingui.py", line 1872, in send_new_mixer_stats
    if self.prefs_window.dual_volume.get_active():
       ^^^^^^^^^^^^^^^^^
AttributeError: 'MainWindow' object has no attribute 'prefs_window'
$

My inxi -Aaz:

Audio:
  Device-1: Intel Comet Lake PCH-LP cAVS vendor: Lenovo
    driver: sof-audio-pci-intel-cnl alternate: snd_hda_intel, snd_soc_avs,
    snd_sof_pci_intel_cnl bus-ID: 00:1f.3 chip-ID: 8086:02c8 class-ID: 0403
  API: ALSA v: k6.16.4-arch1-1 status: kernel-api
    tools: alsactl,alsamixer,amixer
  Server-1: PipeWire v: 1.4.7 status: active with: 1: pipewire-pulse
    status: active 2: wireplumber status: active 3: pipewire-alsa type: plugin
    4: pw-jack type: plugin tools: pactl,pw-cat,pw-cli,wpctl

Let me know if more info is needed.

[Moonbase]

For some obscure reason, it works again (still same AUR package). Maybe a kernel issue? Now running kernel 6.16.5-arch1-1. The only other thing I tried (then without success) was starting over with a new fresh profile.

Thanks for the ongoing development! Love the new features like VoIP input grabbing with regex, that could come in handy if you’re using SIP landlines and clients like Linphone!

Can I myself close this somehow?

[Stephen Fairchild]

Isn't technology wonderful!

[Moonbase]

Indeed…